class LogicalClock {
public:
    ...

    // sets new time if the newTime > _clusterTime and the newTime passes validation.
    // Return OK if time is updated
    // Returns SignatureDoesNotMatch on signature mismatch.
    Status advanceClusterTime(OperationContext* txn, SignedLogicalTime newTime) {
        // TODO: grab mutex here

        if (_lastLogicalTime.getTime() >= newTime.getTime()) {
            return Status::OK();
        }

        if (!passesRateLimiter(newTime)) {
            return {ErrorCodes::CannotAdvanceLogicalClock, ""};
        }

        if (autoOn) {
            if (!hasEnoughPrivilege(txn)) {
                auto mySignature = _hmacService->sign(newTime.getTime().serialize());

                if (mySignature != newTime.getSignature()) {
                    return {ErrorCodes::SignatureDoesNotMatch, ""};
                }
            }
        }

        _lastLogicalTime = std::move(newTime);
    }
}